pH effect on hydrothermal synthesis of the coordination polymers containing pyrazine-2,3-dicarboxylate: Investigation of thermal stability, luminescence and electrical conductivity properties

Abstract

Hydrothermal reactions of the lanthanide(III) salt with 2,3-pyrazinedicarboxylic (2,3-pzdc) acid yielded the coordination polymers [La2(2,3-pzdc)3(H2O)]n.3nH2O (1) and [La2(2,3pzdc)3(H2O)]n.2nH2O (2). Compounds were obtained in a three dimensional form with different pH values under subcritical water conditions. The structures had variable coordination numbers. In addition, pH values play an important role in the structural chemistry of these materials. Different characterization techniques (elemental analysis, FT-IR, ICP-OES, TG/DTA, FESEM, PXRD, BET and single crystal X-ray) were carried out to confirm crystallinity, porosity, purity and chemical composition of the coordination polymers. Crystal structures of the polymers were examined in detail. Their thermal stability, luminescence and electrical conductivity properties were investigated in the solid state.